1. Field of the Invention
The present invention pertains generally to the field of Thermoelectric Devices, more particularly to the field of materials and treatments yielding improved efficiency in thermoelectric devices.
2. Background of the Invention
Thermoelectric (TE) devices convert heat directly to electrical power, or conversely, create heating or cooling directly from electrical power. The devices are entirely solid state, with no moving parts to wear out. They are very rugged and can last indefinitely. Their main shortcoming has been their low efficiency. The low efficiency relegates TE devices to a few applications where their simplicity and ruggedness outweighs the inefficiency, such as sensors and waste heat energy converters. More recently, advances in semiconductor TE devices have made practical small coolers and temperature controllers that can both heat or cool as needed to control a temperature. Applications range from cooling computer chips to appliances for the home.
The potential for TE devices, however, is much greater. If the efficiency can be increased, TE devices can begin to supplant mechanical compressor refrigeration systems, gasoline generators, geothermal power production and more. TE devices could play a significant role in the energy production, home heating/cooling and general energy management of the future.
More recent advances in TE devices have shown that quantum dot and superlattice structures combined with semiconductor technology can produce even higher efficiency factors. One such example is disclosed in U.S. Pat. No. 6,605,772, wherein Pb Se Te/Pb Te quantum dot superlattice structure was found capable of a figure of merit (ZT) of 0.9 near room temperature (300K).
Although improvements have been made, further improvement in efficiency is needed before TE devices can compete with the energy conversion machines that presently dominate industry. To reach their full potential, these improvements will need to use techniques that can be manufactured economically and result in rugged and reliable devices.
Therefore there is a clear need for thermoelectric devices that have improved efficiency, are easy to manufacture, and are rugged and reliable devices in the field.